The present embodiment relates to a system in which the output from a plurality of image marking engines is selectively directed to one of a plurality of output modules which supply a finishing function. It finds particular application in conjunction with an integrated system of printers, each having the same or different printing capabilities, which feed printed media via a common network to a plurality of finishing modules, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications.
In a typical xerographic apparatus, such as a copying or printing device, an electronic image is transferred to a print medium, such as paper. In a xerophotographic process, a photoconductive insulating member is charged to a uniform potential and thereafter exposed to a light image of an original document to be reproduced. The exposure discharges the photoconductive insulating surface in exposed or background areas and creates an electrostatic latent image on the member, which corresponds to the image areas contained within the document. Subsequently, the electrostatic latent image on the photoconductive insulating surface is made visible by developing the image with developing powder referred to in the art as toner. This image may subsequently be transferred to a support surface, such as paper, to which the toner image is permanently affixed in a fusing process. In a multicolor electrophotographic process, successive latent images corresponding to different colors are formed on the insulating member and developed with a respective toner. Each single color toner image is transferred to the paper sheet in superimposed registration with the prior toner image. For simplex printing, only one side of a sheet is printed, while for duplex printing, both sides are printed.
Other printing processes are known in which the electronic signal is reproduced as an image on a sheet by other means, such as through impact (e.g., a type system or a wire dot system), or through use of a thermosensitive system, ink jets, laser beams, or the like. To meet demands for higher outputs of printed pages, one approach has been to increase the speed of the printer, which places greater demands on each of the components of the printer.
Another approach has been to develop printing systems which employ several small marking engines. These systems enable high overall outputs to be achieved by printing portions of the same document on multiple printers. Such systems are commonly referred to as “tandem engine” printers, “parallel” printers, or “cluster printing” (in which an electronic print job may be split up for distributed higher productivity printing by different printers, such as separate printing of the color and monochrome pages. Examples of such a system are described in above-mentioned application Ser. Nos. 10/924,459 and 10/917,768. Such a system feeds paper from a common source to a plurality of printers, which may be horizontally and/or vertically stacked. Printed media from the various printers is then taken from the printer to a finisher where the sheets associated with a single print job are assembled.
Print shops and other users of such systems seek an increased variety of functions in the finisher to meet customer demands. The finisher may incorporate several different functions, such as folding, stapling, collating, binding, and the like. As a result, a typical finisher represents a substantial investment. As a new function becomes available or is improved, a print shop which does not have a finisher which delivers that function may loose a portion of its business.